Senior Data Scientist (f/m/d) adjoe is redefining the future of mobile ads. Powered by advanced AI, first-party data and world-class engineers, we’ve perfected the offerwall experience for monetizing and scaling app publishers with solutions like Playtime – now the fastest growing rewarded advertising channel globally – driving incremental engagement, retention, and revenue. Together, this ecosystem connects app developers to over 770 million users worldwide for scalable growth. We are a profitable, high-growth company backed by a $100 million investment from Bertelsmann. Operating from offices in Hamburg, Boston, Singapore, and Tokyo, adjoe is defining the next stages of app and ad experience – right now. Join us. Meet Your Team: Playtime Data Science Playtime is a time- and event-based ad unit that continuously rewards users with in-app currency – for the time they spend and events completed while playing mobile games. We connect advertisers to 700+ million Playtime users and serve 2bn requests per day at low latency. We ensure that all parties involved have a positive experience. Advertisers get more users for their apps. Monetizers earn revenue for users on their platforms. Users play fun games while simultaneously getting rewarded. Our data science team powers the engine that distributes our ads. They solve multiple tasks such as developing algorithms to provide the most relevant ads for users, predicting user interests and inclinations, and dynamically adjusting pricing based on these predictions. Because the user base is very diverse we are using deep learning models that we could show to be able to serve the best ads to users. Within the Playtime team you will be responsible for services and models that we use to provide automated solutions both for our advertisers and publishers. \nWhat you will do: Translate complex product requirements into actionable machine learning solutions. Build robust models to predict user behavior, e.g. LTV and conversion prediction, optimizing retention, advertiser’s ROAS (return on advertising spend) and other dynamic values. Leverage state-of-the-art deep learning algorithms, ensuring each solution is fit-for-purpose and impact-driven. Own the ML lifecycle from end-to-end: extracting insights from terabytes of user behavior data, developing models, validating them through A/B testing, and guiding them into production. Partner closely with Backend, Infrastructure, and Analytics teams to ensure seamless model integration and system stability. Present your findings and solutions to product and business stakeholders, clearly communicating the impact of your work on product KPIs. Who you are: You have 5+ years of professional experience in the Data Science field. You have a history of successfully deployed models that have made a measurable impact on business and product goals. You have a strong knowledge of Python and main Data Science libraries: pytorch/tensorflow, pandas/polars, numpy, scikit-learn, lightGBM/catboost/xgboost. You have experience developing deep learning models and have applied them already in a production environment with a large amount of traffic (>1 million predictions per day). You have advanced SQL skills and experience drilling into large amounts of data using distributed query engines (e.g., AWS Athena, Trino, Spark). You can explain complex mathematical foundations in simple, non-technical terms. You are comfortable in translating product language into ML logic and vice-versa. You are open to relocating to Hamburg, Germany. Big Plus: Experience in the AdTech industry. Plus: Tech & Infrastructure knowledge: Airflow, hosting models, deploying models. Fuel for the Journey: Benefits to Support Your Ambitions Invest in Your Future: Regular feedback and our development program support your growth, helping you expand your skillset and achieve your career goals. Easy Arrival to adjoe: From signing to settling in Hamburg, we’ve got you covered. Need a visa? No problem. Ready to build your new life and career at adjoe in Hamburg? We support every ambition—from learning German to a relocation bonus that helps you settle in and make Hamburg feel like home. Live Your Best Life, at Work and Beyond: We work in a hybrid setup with 3 core office days, plus flexible working hours. Enjoy 30 vacation days, 3 weeks of remote work per year, and free access to an in-house gym with lots of different fitness classes and mental health support through our Employee Assistance Program (EAP). Thrive Where You Work: Enjoy the Alster lake view from our central office with top-notch equipment, fun open spaces, and a large variety of snacks and drinks. Join the Community! Participate in regular team and company events, including hackathons and social gatherings. We work together, and we celebrate together, too. \n